HOW OFTEN SHOULD YOU REPLACE YOUR WATER PUMP IMPELLER, AND WHAT SHOULD THAT COST, ROUGHLY, TO HAVE DONE BY A MARINA? ON AN OUTBOARD?

every two years.
the kit for my yamahas were 35 bucks..
pretty simple to do it yourself.
theres a thread on thehulltruth somewhear that shows step bye step with pics.

THANKS F F, JUST AFRAID TO SCREW WITH IT IN WARRANTY, I'VE HEARD HORROR STORIES ABOUT THEM NOT COVERING REPAIRS BECAUSE MAITANANCE WAS DONE BY OWNER.

It's easy and well worth the investment getting it done every 2 years and the thermostats at the same time.
At a service center it may cost you 150 to get both done as the same time.

well if you are me and you have an old 74 merc then you replace it once a year if you are lucky, the impeller/gaskets was 15 bucks the whole water pump kit was 105 if i remember correctly. Not that hard to replace yourself. Took me about 2 hours the first time and I had no idea what I was doing. (second time the motor caught on fire but thats a story for another time)

Thermostat was pretty easy too. Just make sure you have all the gaskets.

mr hunters, I thought you replaced that stuff every time that you used it
:rotfl: :rotfl: :rotfl: :rotfl: :rotfl:

Mr hunter, want to make some cash? A fire?

A dealer would charge $250-$350

ok ill tell the story quickly.
the lower unit was being difficult to put back on.. driveshaft wasnt lineing up correctly.

so after about 30 minutes of wrestling with the thing i decided to force things... keep in mind that it is an old 74 65hp 3banger merc. It has a wierd issue that when tilted the carb leaks gas, not a little.. but whatever is in the carb at that moment. the positive wire going to the battery is frayed (which i found out was an issue) and the rocking of the boat while i tryed to put the lower unit in must have cause a spark.

Spark plus gas = a very bad day.

battery wires are being replaced before next year :)

tajon;
yep went through 3 last year... but thats just because I couldnt find the coolant problem.